Dermatome

ABSTRACT

The invention relates to a dermatome as used for surgical purposes to sever a strip of skin from a patient&#39;&#39;s body prior to transplantation. The invention lies in an adjustment device having an adjustment screw received in a threaded bore of a crossmember connecting the sidewalls of the cutting head of the dermatome. The lower extremity of the adjustment screw loosely engages a recess formed in a pivotally mounted gauge bar disposed forwardly of the cutting blade. This gauge bar with its recess is constantly urged b spring action, assisted by the contact pressure during operation of the dermatome, against the lower extremity of the adjustment screw. The gauge bar is drivingly connected via a leverage transmission with an indicator journaled on the cutting head and cooperating with a stationary scale. In a preferred embodiment the cutting blade is loosely placed in the cutting blade holder and prevented against shifting by positioning means. The cutting blade is resiliently clamped against the cutting blade holder by a pivotal cover engaging the cutting blade near its cutting edge. This cover does not move during the cutting operation of the dermatome and forms a guiding ramp for the severed strip of skin.

United States Patent [72] Inventors Fritz Georg Pohl;

Arnold Keller, both 01 Kiel-Dietrichsdorl, Germany (21] Appl. No.649,254

[22] Filed June 27,1967

[45] Patented June 8, 1971 [7 3] Assignee Austeual Europa, Inc.

Klel-Dletrichsdorl, Germany [54] DERMATOME 6 Claims, 8 Drawing Figs.

[52] US. Cl 128/305 [51] ....A6lb17/322 [50] Field 01 Search 128/305,

w13,ss3,403

Assistant ExaminerRichard J. Apley Attorney-Beaman & Beaman ABSTRACT:The invention relates to a dermatome as used for surgical purposes tosever a strip of skin from a patients body prior to transplantation. Theinvention lies in an adjustment device having an adjustment screwreceived in a threaded bore of a crossmember connecting the sidewalls ofthe cutting head of the dermatome. The lower extremity of the adjustmentscrew loosely engages a recess formed in a pivotally mounted gauge bardisposed forwardly of the cutting blade. This gauge bar with its recessis constantly urged b spring action, assisted by the contact pressureduring operation of the dermatome, against the lower extremity of theadjustment screw. The gauge bar is drivingly connected via a leveragetransmission with an indicator joumaled on the cutting head andcooperating with a stationary scale. in a preferred embodiment thecutting blade is loosely placed in the cutting blade holder andprevented against shifting by positioning means. The cutting blade isresiliently clamped against the cutting blade holder by a pivotal coverengaging the cutting blade near its cutting edge. This cover does notmove during the cutting operation of the dermatome and forms a guidingramp for the severed strip of skin.

PATENTED JUN 8|Q7l 3; 5833103 sum 1 UF 2 xxmmm m W Y. NVENTOR5 4% Jam,

PATENTEDJUN 8|97l 3583, 103

' sum 2 [IF 2 DERMATOME DESCRIPTION OF THE PRIOR ART Dermatomes of thistype are known which comprise: a cutting head the underside of whichforming a sliding surface sliding along over the skin during the cuttingprocedure, this sliding surface being defined forwardly by a sharp edgeextending transversely to the direction of sliding; a cutting bladesupported in the cutting head and arranged obliquely relative to thesliding surface, abutting the sharp edge, and projecting with itscutting edge into the cutting surface defined by the sliding surface; agauge bar arranged within the cutting head forwardly of the sharp edgewith respect to the direction of sliding, and including a gauge edgeextending in spaced parallel relation to the sharp edge, and defining aguide surface extending in a forward direction therefrom, said gauge barbeing pivotally supported about an axis extending in parallel relationto said gauge edge; adjustment means for pivoting said gauge bararranged in a crossmember connecting the sidewalls of the cutting head,and including an adjustment screw engaging said gauge bar in spacedrelation from said pivot axis; and indicating means for the cuttingdepth defined by the normal distance between said gauge edge and saidcutting surface.

This known dermatome has a gauge bar with a curved sliding surface, thelowermost point of which being disposed approximately at the cuttingedged of the cutting blade. When a strip of skin is severed the roundedsliding surface of the gauge bar causes bulging of the skin directly infront of the cutting edge of the cutting blade whereby the exactmaintenance of the cutting depth is impaired, which may be prevented ifa gauge bar with a planar sliding surface is used. But the essentialdrawback of this known dermatome must be seen in the adjustment devicefor the gauge bar, and also in the indicating device of the cuttingdepth. A micrometer screw serves as adjustment device mounted rotatablybut axially nonshiftably in the crossmember connecting the sidewalls ofthe cutting head. The micrometer screw is screwed into a threaded boreof the gauge bar. Since the micrometer screw can only be rotated, but isotherwise fixed in its position relative to the crossmember, and since,upon adjustment of the cutting depth, the gauge bar is caused to pivotabout its pivot axis, the axis of the threaded bore and the axis of thescrew can only coincide in one position, but must include an obtuseangle in any other position. Therefore, it is necessary, if in thismanner an adjustment of the cutting depth is to be obtained at all, toprovide so much clearance either in the bearing support of themicrometer screw, or between the interior and exterior thread that aprecise adjustment is impossible.

Another drawback is to be seen in the indicating device for the cuttingdepth. The end face of the head of the micrometer screw is provided withan angular graduation which, corresponding to the pitch of the thread,represents from scale mark to scale mark a defined adjustment measure ofthe cutting depth. If one starts out from the fact that a dermatomeshould have an adjustment range between and 2 mm. then the pitch of themicrometer screw should be 2 mm., if the total adjustment range is to becovered with one revolution of the micrometer screw. A screw with such ahigh pitch cannot be considered as micrometer screw. However, if alesser pitch of the thread is provided correspondingly more revolutionsof the screw become necessary, if the cutting depth is to be ad justedover the total range. But in this case the operator of the apparatusdoes not know whether the screw had been adjusted already prior to itsuse out of the zero position so that this, being of the opinion that themicrometer screw had been in a zero position but in fact was not, mightlead to serious mistakes. But even if this known dermatome provides anadjustment range and therefore a pitch of 2 mm., which would require amultiple thread, so as to avoid the aforementioned errors then this highpitch in connection with the first-mentioned drawback regarding thenecessary clearance would cause a still greater inaccuracy regarding thefine adjustment.

In this known dermatome, from which the invention starts out, thecutting blade is screwed by hexagon head screws on the blade holder, theheads of which project beyond the upper surface of the holder. 0n theone hand the replacement of the cutting blade is in this constructioncumbersome and not possible without using a spanner.

In addition, the upper surface of the blade holder forms a guide pathfor the severed strip of skin. Since the cutting knife in severingstrips of skin reciprocates and, besides this, the mounting screws ofthe blade project into the guide pathof the severed strip of skin, it isnecessary, for avoiding damages of the strip of skin, that the latter isseized by a second person immediately upon severance and kept clear ofthe upper blade surface.

In another known dermatome one has chosen a construction of theadjustment device for the gauge bar inverted to that one of theabove-described dermatome. In this case the adjustment screw is screwedinto the crossmember connecting the sidewalls of the cutting head. Theend of the adjustment screw is formed as a tenon provided with acircumferential groove. The tenon engages a bore of the gauge bar and issecured thereto rotatably but axially nonshiftably by a pin provided inthe gauge bar and extending tangentially through the circumferentialgroove. Also in this case the same drawback may be observed as in caseof the prior-described dermatome, because, if the gauge bar is to beadjusted by pivoting motion, there must be ample clearance between thepin and the circumferential groove of the tenon so that, in view of sucha loose connection, an exactly adjustable cutting depth and maintenanceof the same cannot be expected. An indicating device for the cuttingdepth is not provided so that the cutting depth must be guessed, whichshould be avoided under all circumstances.

Further dermatomes are known in which the adjustment movement of thegauge bar is not pivotal but a linear movement in straight line guide.This is advantageous in that the guide surface of the gauge bar isalways disposed in approximately parallel relation to the cutting plane,and in that the guidance and holding of the gauge bar is unobjectionableand free of play, however is afflicted with the disadvantage ofsubstantially higher manufacturing costs, and the more difficultdisassembly of the apparatus for the purpose of cleaning andsterilizing. In this it is known to provide a stationary adjustmentscale at one of the sidewalls of the cutting head for predetermining thecutting depth. An indicator is moving above the scale simultaneouslyserving as actuator for the adjustment device. The indicator is rigidlymounted on an eccentric shaft, by rotation of which the gauge bar may beshifted upwardly or downwardly. This type of adjustment device isexpensive in manufacture, because it requires precise machining of thecam surfaces cooperating with the eccentrics. In addition the eccentricsrequire accurate setting which is done by the manufacturer. A furtherdrawback is to be seen in the fact that equal angular rotations of theeccentric shaft do not result in equal movements of the gauge bar, sothat the spacings of the scale marks become uneven, if they are toindicate equal strokes of the gauge bar, and this again complicates theproduction.

This invention aims to improve the initially described dermatome in sucha manner that, in spite of a simple construction, allowing a quick andeasy disassembly for cleaning and sterilization, an essentially moreprecise adjustment and maintenance of the cutting depth is achieved,than is attainable in the known apparatus. In addition an indicatingdevice for the cutting depth is to be provided having a range from 0 to2 mm., in which errors of the adjustment are avoided, and in which equalmovements of the gauge bar are transmitted into equal movements of theindicator, so that the indicating scale has marks evenly spaced.Further, in a preferred embodiment a novel mounting of the cutting bladeis to be provided which is very simple in construction, allows an easyand quick replacement of the cutting blade, without requiring any tools,and which, at the same time, provides a smooth not movable guide andsliding surface for the severed strip of skin extending over the entirewidth of the apparatus, thereby requiring only one person for itsoperation.

SUMMARY OF THE INVENTION According to the invention the problem issolved in that the adjustment screw of the adjustment means is screwed,in a manner known per se, into a threaded bore of the crossmember of thecutting head, and that the lower end of the adjustment screw looselyengages a recess formed in the gauge bar, which latter is urged inconstant abutment against the adjustment screw by the contactingpressure of the apparatus, assisted by spring means, and that theindicating means for the cutting depths comprise a stationary scale,known per se, and an indicator journaled on the cutting head anddrivingly connected by a leverage transmission with the gauge bar.

A very suitable embodiment which prevents bulging of the skinimmediately in front of the cutting edge of the blade and which assuresthat the skin is severed accurately with an even thickness is obtainedwhen the gauge bar has a planar guide surface defined at the sideopposite of the adjustment edge by a rounded, charnfered edge extendingin parallel relation to the adjustment edge, and when the pivot axis isarranged adjacent the rounded, chamfered edge and is formed by axlejournals extending through the sidewalls of the cutting head andengaging into bores provided in the gauge bar. In this an advantageouseffect is achieved when at a maximum cutting depth, the guide surface ofthe gauge bar is disposed substantially in parallel relation to thesliding surface of the cutting head and includes an obtuse angle withthe sliding surface at smaller cutting depths.

A preferred construction of the indicating means provides that theindicator of the indicating means and the scale are arranged, in amanner known per se, at one of the sidewalls of the cutting head, andthat the indicator is rotatably supported at the sidewall on an axisextending in parallel spaced relation to the pivot axis of the gauge baradjacent its adjustment edge, and further that an indicator drive pinextending in spaced relation to the indicator axis and secured to thegauge bar extends through an aperture of the sidewall and projects intoan elongated hole of the indicator, and that the length of the indicatorand the spacings of the axes between the pivot axis of the gauge bar andthe indicator drive shaft, as well as between the latter and theindicator axis are chosen in accordance with a defined transmissionratio.

In order to facilitate the width adjustment of the skin to be severedthe invention provides that the cutting head is provided in a mannerknown per se, with adjustment sliding shoes for adjusting the width ofthe cut.

An especially suitable embodiment of the invention which allowsoperation of the dermatome by a single person and yet avoids withcertainty that the severed skin is damaged by the oscillating cuttingblade is characterized in that the cutting blade is loosely insertableinto the cutting blade holder and is held in its position by positioningmeans, and that a cover is provided arranged above the cutting bladeholder and is pivotally supported about an axis extending in parallel,rearwardly spaced relation to the cutting edge of the blade, the forwardedge of said cover engaging resiliently the cutting blade arrangedtherebelow, and that the upper surface of the cover forms a stationaryguide path for the severed strip of skin. In this embodiment thesidewalls of the cutting head are provided with bosses having threadedbores formed therein into which screws extending through the cover arethreaded, a compression spring being arranged between each head of thescrews and the cover, whereby the cutting blade is resiliently urgedagainst the oscillating cutting blade holder.

The positioning means for the cutting blade of this embodiment maycomprise two spacedly arranged projections provided on the cutting bladeholder and engaging corresponding apertures provided in the cuttingblade.

Suitable embodiments of the subject matter of the invention shall now beexplained by way of example in connection with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. II shows a front elevational view of the cutting head of adermatome in accordance with the invention;

FIG. 2 shows a top view of the cutting head according to FIG. 1;

FIG. 3 shows a cross-sectional view along the line 3-3 of FIG. 2;

FIG. 4 shows a side view of the dermatome cutting head shown in FIG. lto 3;

FIG. 5 shows in a diagrammatic manner the important members of thecutting head according to the invention, substantially in correspondencewith FIG. 3, but in an enlarged scale;

FIG. 6 shows a longitudinally sectional elevation of a dermatome inaccordance with the invention, however, in a modified and improved,preferred embodiment;

FIG. 7 shows a partial longitudinal sectional view in an enlarged scaleof the dermatome illustrated in FIG. 6; and

FIG. 8 shows a top view of the apparatus according to FIGS. 6 and 7 withthe cover removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings FIGS. I to 5 theillustrated cutting head comprises a baseplate 28, the underside ofwhich forming a sliding surface 2. The forward end of this baseplateforms a knife edge 3 on which a cutting blade 4 rests, which issupported in the cutting head and projects with its cutting edge 5 intothe cutting plane defined by the sliding surface. The mounting means ofthe cutting blade 4 are not shown in the drawings. Sidewalls l3 and 14extend upwardly from the lateral edges of the baseplate 28, and projectforwardly beyond the knife edge 3, the upper edges of the sidewalls l3and M are connected by a crossmember 20. Rearwardly, the sidewalls I13and M are connected by a crossmember 20. Rearwardly, the sidewalls l3and 14 extend to holding means for the cutting head (not shown). Belowthe crossmember 20 a substantially square gauge bar 6 is pivotallysupported by axle journals extending through the sidewalls l3 and 14 andprojecting inwardly into bores of the gauge bar 6. The axle journalsmay, for example, form parts of screws screwed through threaded bores ofthe sidewalls l3 and M. The gauge bar 6 is disposed in sliding directionforwardly of the knife edge 3 and the cutting edge 5, and includes anadjustment edge 7 extending substantially in parallel, spaced relationto the knife edge 3 and the cutting edge 5 of the blade 4, whichadjustment edge 7 may be lifted, or lowered respectively, relative tothe cutting edge 5 of the blade 4! by pivoting the gauge bar 6 about theaxis Ill. The underside of the gauge bar 6, extending forwardly from theadjustment edge 7, forms a guide surface smoothening the skin bulging infront of the dermatome during the cutting operation, and thereby feedingthe skin in a proper manner to be cut towards the cutting edge 5 of theblade 4. The normal distance between the adjustment edge and the cuttingplane formed by the sliding surface 2 defines the cutting depth. Thecutting width is determined by two sliding shoes 27 extending on eitherside over the lateral edges of the knife edge and the cutting edge 5 ofthe blade. The sliding shoes 27 are mounted on two supports 29. Eachsupport 29 includes an upper and a lower bore through which guide rods30 and 31 extend, and a threaded bore is disposed between the guidebores of each support 29 and receives a threaded spindle common for bothsupports 29. This threaded spindle is over each half of its lengthprovided with rightand left-hand threads, whereby, upon rotation of thethreaded spindle by means of the knurled knob 33, the two supports 29and thus the two sliding shoes 27 are moved simultaneously in oppositedirections. The guide rods 30 and 31, as well as the threaded spindle 32are supported in the forward ends of the side walls 13 and 14.

The adjustment of the gauge bar 6 is achieved by means of an adjustmentdevice 9. This adjustment device 9 comprises as an essential member anadjustment screw disposed in a threaded bore 17 of the screw member 20,and provided at its upper end with a knurled knob 34. The adjustmentmember proper is formed by a downward extension 12 of the adjustmentscrew. The lower end of the adjustment member 12 seats on an abutmentpoint 16 within a recess 21 of the gauge bar 6. This abutment point 16is, with respect to the pivot axis 11 of the gauge bar 6, rearwardlyspaced. The gauge bar 6 is urged against the adjustment member 12 of theadjustment screw by two tension springs 19. These springs 19 are securedwith their one ends to the gauge bar 6 at points rearwardly spaced withrespect to the pivot axis 11, in the same manner as the abutment point16, and with their other ends to fixed points of the cutting head. Inthis zone an indicator drive pin 26 extends cutting process one of theside surfaces of the gauge bar 6 and projects through an aperture in oneof the sidewalls 13 beyond its other surface, where it drivingly engagesinto an aperture of the indicator 22. The indicator 22 is rotatablyjournaled in the sidewall 13 about an axis 23, for example formed by athreaded pin, and moves over a scale 25 arranged on this sidewall.Depending on the chosen distance between the indicator drive pin 26 andthe indicator axis a more or less greater transmission ratio, and thus amore or less spaced scale graduation is obtained. As particularlyevident from P16. 3, the sliding surface 2 and the guide surface 8 ofthe guage bar include an obtuse angle when the cutting depth is set tozero, Le. a disappearingly normal distance between the adjustment edgeof the gauge bar 6 and the cutting edge 5 of the blade 4. However, at amaximum cutting depth the guide surface 8 and the sliding surface 2extend substantially in parallel relation. By means of this change ofthe angle of approach between the sliding surface and the guide surfacethe bulging skin caused during the cutting process in front of thecutting head is pressed together in such a manner that at any cuttingdepth a smooth, continuous cut is achieved.

The mounting means of the cutting blade 4 (in FIG. 1 to 5 notillustrated) is attached in a known manner, to drive means laterallyreciprocating the cutting blade 4.

As may be seen from FIGS. 6 to 8 a preferred improved embodiment of thedermatome according to the invention consists of a cutting head 100 towhich a handle 101 with a builtin motor (not shown) is secured. On thefreely projecting end of the motor shaft 102 and eccentric roll isjournaled engaging into a fork 104 of a cutting blade holder 105, to bedescribed in detail yet, so as to drive the same in a laterallyreciprocating manner.

The cutting head 100 is construed in form of a shovel, comprising abaseplate 106 the underside of which forming a sliding surface 107 withwhich the dermatome is slidingly guided across the skin to be severed.The forward end of the baseplate is chamfered under an acute angletoward the sliding surface 107, thereby forming a backing surface 108 onwhich the forward end of the cutting blade holder 105 rests which isalso chamfered so as to form a continuation of the sliding surface 107of the base plate 106 of the cutting head 100.

The cutting head further includes side walls 109 and a rear wallcarrying the handle 110. On an axis 111 extending transversely to thesidewalls 109 the cutting blade holder 105 is slidingly and pivotallysupported. Adjacent the forward end the cutting blade holder is,according to the invention, provided with two upwardly projecting pins112 spaced relative to each other, which pins serve to receive andposition the cutting blade 114 provided with corresponding apertures,similar to a razor blade of a shaving apparatus, wherein the cuttingedge of the blade 114 projects a small distance beyond the forward edge115 of the cutting blade holder 105.

According to the invention a cover 116 is provided above the cuttingblade holder extending between the sidewalls 109 of the cutting headover its entire width. The cover 116 is secured to the cutting head 100by two screws 117 with knurled heads one arranged on either side. Thesescrews extend through corresponding holes 118 in the cover 116 and arescrewed into threaded bores 119 of eyes 120 provided on the sidewalls109. Compression springs 122 are arranged between the knurled heads 121of the screw 117 and the upper surface of the cover 116 resilientlyurging the cover 116 downwardly. The cover extends slantedly downwardlytowards the cutting blade and engages with its forward end resilientlythe cutting blade a small distance rearwardly spaced from the cuttingedge of the cutting blade 114, which in this way is clamped between thereciprocatingly driven cutting blade holder 105 and the stationary cover116.

Thus on the one hand the cover serves as a clamping element for holdingthe cutting blade 114, but on the other hand it also forms a stationaryguiding ramp for the strip of skin severed by the cutting blade, pastwhich the same may slide unobstructedly, so that damages of the trip ofskin, the thickness of which may vary between 0.2 and 2 mm., are surelyavoided. Further, it is not necessary anymore that, as was commonpractice, a second person has to seize the strip of skin immediatelyupon severance by the cutting blade and to lift it free of thereciprocating cutting blade in order to avoid damages of the skin.

An adjustment device 123 for adjusting the cutting depth is arranged infront of the cutting blade 114, and includes a gauge bar supported topivot about an axis 124 extending in parallel relation to the cuttingedge of the cutting blade. This gauge bar 125 is pulled into abuttingengagement against the face of an adjustment screw 127 by tensionsprings 126. The adjustment screw 127 extends through a threaded bore128 provided in a crossmember 129 connecting the two sidewalls 109 ofthe cutting head. The gauge bar 125 is drivingly connecting via a leverarrangement with an indicator moving over a scale provided on one of thesidewalls 109.

The adjustment device 123, and the indicating device for the cuttingdepth cooperating therewith, have been described in detail with regardto the embodiment shown in F168. 1 to 5.

It is to be understood that modifications within the limits of theattached claims are possible without departing from the scope of theinvention. Thus, instead of the two positioning pins 112 also anelongated ledge may be provided engaging into a corresponding slot ofthe cutting blade. Also, the arrangement could be inverted by providingthe positioning means on the cutting blade and the receiving aperture,or apertures respectively, in the cutting blade holder. Further, it ispossible to construct the mounting means of the cover 116 in a differentway, for example by pivotally hooking the cover to the cutting head andurging it downwardly by lead springs, adapted to be moved out of theway.

What we claim is:

1. A dermatome comprising in combination, a cutting head, a slidingsurface defined on said head adapted to engage and slide over the skinduring the cutting procedure, said surface intersecting a sharp edgeextending toward and transversely to the direction of sliding, a cuttingblade supported in said cutting head and arranged obliquely relative tosaid sliding surface engaging said sharp edge and including a cuttingedge disposed adjacent said sharp edge of said sliding surface, anelongated gauge bar pivotally mounted on said cutting head forwardly ofsaid sharp edge and said cutting edge with respect to the direction ofoperative movement, a flat, planar, gauge edge defined on said gauge barextending in spaced parallel relation to said sharp and cutting edgesdefining a guide surface, said gauge bar being pivotally supported onsaid head about an axis parallel to said gauge edge and cutting edge,adjustment means mounted on said head for pivoting said gauge bar aboutsaid axis to vary the relationship of said gauge edge to said cuttingedge, indicating means mounted on said head indicating the angularrelationship of said gauge bar to its pivot axis to indicate therelationship of said gauge edge to said cutting edge and the depth ofcut being taken, said indicating means including an indicator drive pinaffixed to said gauge bar offset with respect to said gauge bar pivotaxis, an indicator pivotally mounted upon said cutting head, indiciadefined on said cutting head adjacent said indicator, and con nectingmeans interconnecting said indicator drive pin and said indicatorwherein pivotal movement of said gauge bar about said axis is indicatedby said indicator.

2. A dermatome as in claim 1 wherein said adjustment means includes anadjustment screw threaded upon said cutting head, said screw having alower end disposed toward said gauge bar, a recess defined in said gaugebar offset with respect to said pivot axis receiving said screw lowerend, and biasing means pivoting said gauge bar in a directionmaintaining said screw lower end in engagement with said recess whereinadjustment of said screw adjusts the angular relationship of said gaugebar to its axis.

3. A dermatome as in claim 1 wherein said gauge bar includes a forwardlydisposed rounded, chamfered edge extending parallel to said gauge edge,and said pivot axis is disposed adjacent said rounded, chamfered edgeand is defined by axle journals extending through sidewalls defined uponsaid cutting head and received within bores defined in ends formed onsaid gauge bar.

4. A dermatome as in claim 1 wherein said cutting head includes acentral forward region disposed forwardly of said gauge bar and cuttingedge with respect to the direction of operative movement, a pair ofcutting edge protective shoes slidably mounted upon said cutting head, ashoe being located at each lateral side of said head with respect tosaid central region and forwardly of said cutting edge preventingengagement of said cutting edge with the skin being cut at the locationof said protective shoes and adjusting means for simultaneously movingsaid protective shoes toward and away from said central region.

5. In a derrnatome as in claim 11, means mounted upon said cutter headfor laterally reciprocating said cutting blade, a

cover mounted upon said cutting head disposed adjacent and above saidcutting edge, and rearwardly therefrom with respect to the direction ofoperative movement for receiving the skin being cut, said meanssupporting said cutting blade supporting said cover in a stationarymanner with respect to said cutting head.

6 A dermatome comprising, in combination, a cutting head, a slidingsurface defined on said head adapted to engage and slide over the skinduring the cutting procedure, said surface intersection a sharp edgeextending toward and transversly to the direction of sliding, a cuttingblade supported in said cutting head and arranged obliquely relative tosaid sliding surface engaging said sharp edge and including a cuttingedge disposed adjacent said sharp edge of said sliding surface, anelongated gauge bar pivotally mounted on said cutting head forwardly ofsaid sharp edge and said cutting edge with respect to the direction ofoperative movement, the rear and bottom planar surfaces of said gaugebar converging in a sharp gauge edge extending in spaced parallelrelation to said sharp and cutting edges defining a guide surface, saidguage bar being pivotally supported on said head about an axis parallelto said gauge edge and cutting edge, adjustment means mounted on saidhead for pivoting said gauge bar about said axis to vary therelationship of said gauge edge to said cutting edge, indicating meansmounted on said head indicating the angular relationship of said gaugebar to its pivot axis to indicate the relationship of said gauge edge tosaid cutting edge and the depth of cut being taken, said indicatingmeans including an indicator drive pin affixed to said gauge bar offsetwith respect to said gauge bar pivot axis, an indicator pivotallymounted upon said cutting head, indicia defined on said cutting headadjacent said indicator, and connecting means interconnecting saidindicator drive pin and said indicator wherein pivotal movement of saidgauge bar about said axis is indicated by said indicator.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3533,4Q3 Dated June 8. 1971 Inv n fls) Erjtz g, 12 1 and Arnold Keller Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the Abstract, line 9, cancel "b" and subsitute In claim 6, column 8,line 10, cancel "intersection" and substitute -intersecting Signed andsealed this 26th day of October 1 971 (SEAL) Attest:

EDWARD M.FLETCHEH,JR. ROBERT GOTTSCHALK Atteating Officer ActingCommissioner of Patents

1. A dermatome comprising in combination, a cutting head, a slidingsurface defined on said head adapted to engage and slide over the skinduring the cutting procedure, said surface intersecting a sharp edgeextending toward and transversely to the direction of sliding, a cuttingblade supported in said cutting head and arranged obliquely relative tosaid sliding surface engaging said sharp edge and including a cuttingedge disposed adjacent said sharp edge of said sliding surface, anelongated gauge bar pivotally mounted on said cutting head forwardly ofsaid sharp edge and said cutting edge with respect to the direction ofoperative movement, a flat, planar, gauge edge defined on said gauge barextending in spaced parallel relation to said sharp and cutting edgesdefining a guide surface, said gauge bar being pivotally supported onsaid head about an axis parallel to said gauge edge and cutting edge,adjustment means mounted on said head for pivoting said gauge bar aboutsaId axis to vary the relationship of said gauge edge to said cuttingedge, indicating means mounted on said head indicating the angularrelationship of said gauge bar to its pivot axis to indicate therelationship of said gauge edge to said cutting edge and the depth ofcut being taken, said indicating means including an indicator drive pinaffixed to said gauge bar offset with respect to said gauge bar pivotaxis, an indicator pivotally mounted upon said cutting head, indiciadefined on said cutting head adjacent said indicator, and connectingmeans interconnecting said indicator drive pin and said indicatorwherein pivotal movement of said gauge bar about said axis is indicatedby said indicator.
 2. A dermatome as in claim 1 wherein said adjustmentmeans includes an adjustment screw threaded upon said cutting head, saidscrew having a lower end disposed toward said gauge bar, a recessdefined in said gauge bar offset with respect to said pivot axisreceiving said screw lower end, and biasing means pivoting said gaugebar in a direction maintaining said screw lower end in engagement withsaid recess wherein adjustment of said screw adjusts the angularrelationship of said gauge bar to its axis.
 3. A dermatome as in claim 1wherein said gauge bar includes a forwardly disposed rounded, chamferededge extending parallel to said gauge edge, and said pivot axis isdisposed adjacent said rounded, chamfered edge and is defined by axlejournals extending through sidewalls defined upon said cutting head andreceived within bores defined in ends formed on said gauge bar.
 4. Adermatome as in claim 1 wherein said cutting head includes a centralforward region disposed forwardly of said gauge bar and cutting edgewith respect to the direction of operative movement, a pair of cuttingedge protective shoes slidably mounted upon said cutting head, a shoebeing located at each lateral side of said head with respect to saidcentral region and forwardly of said cutting edge preventing engagementof said cutting edge with the skin being cut at the location of saidprotective shoes and adjusting means for simultaneously moving saidprotective shoes toward and away from said central region.
 5. In adermatome as in claim 1, means mounted upon said cutter head forlaterally reciprocating said cutting blade, a cover mounted upon saidcutting head disposed adjacent and above said cutting edge, andrearwardly therefrom with respect to the direction of operative movementfor receiving the skin being cut, said means supporting said cuttingblade supporting said cover in a stationary manner with respect to saidcutting head.
 6. A dermatome comprising, in combination, a cutting head,a sliding surface defined on said head adapted to engage and slide overthe skin during the cutting procedure, said surface intersection a sharpedge extending toward and transversly to the direction of sliding, acutting blade supported in said cutting head and arranged obliquelyrelative to said sliding surface engaging said sharp edge and includinga cutting edge disposed adjacent said sharp edge of said slidingsurface, an elongated gauge bar pivotally mounted on said cutting headforwardly of said sharp edge and said cutting edge with respect to thedirection of operative movement, the rear and bottom planar surfaces ofsaid gauge bar converging in a sharp gauge edge extending in spacedparallel relation to said sharp and cutting edges defining a guidesurface, said guage bar being pivotally supported on said head about anaxis parallel to said gauge edge and cutting edge, adjustment meansmounted on said head for pivoting said gauge bar about said axis to varythe relationship of said gauge edge to said cutting edge, indicatingmeans mounted on said head indicating the angular relationship of saidgauge bar to its pivot axis to indicate the relationship of said gaugeedge to said cutting edge and the depth of cut being taken, saidindicating means including an indicator drive pin affixed to said gaugebar offset with respect to said gauge bar pivot axis, an indicatorpivotally mounted upon said cutting head, indicia defined on saidcutting head adjacent said indicator, and connecting meansinterconnecting said indicator drive pin and said indicator whereinpivotal movement of said gauge bar about said axis is indicated by saidindicator.